Question: The equation of hyperbola $H$ is $\dfrac{x^2}{16}-\dfrac {(y+3)^{2}}{36} = 1$. What are the asymptotes?
Answer: We want to rewrite the equation in terms of $y$ , so start off by moving the $y$ terms to one side: $\dfrac {(y+3)^{2}}{36} = - 1 + \dfrac{x^2}{16}$ Multiply both sides of the equation by $36$ $(y+3)^{2} = { - 36 + \dfrac{ x^2 \cdot 36 }{16}}$ Take the square root of both sides. $\sqrt{(y+3)^{2}} = \pm \sqrt { - 36 + \dfrac{ x^2 \cdot 36 }{16}}$ $ y + 3 = \pm \sqrt { - 36 + \dfrac{ x^2 \cdot 36 }{16}}$ As $x$ approaches positive or negative infinity, the constant term in the square root matters less and less, so we can just ignore it. $y + 3 \approx \pm \sqrt {\dfrac{ x^2 \cdot 36 }{16}}$ $y + 3 \approx \pm \left(\dfrac{6 \cdot (x)}{4}\right)$ Subtract $3$ from both sides and rewrite as an equality in terms of $y$ to get the equation of the asymptotes: $y = \pm \dfrac{3}{2}(x) -3$